Pet food composition containing semi-refined gelling agent

ABSTRACT

A pet food composition containing chunks and a clear gellified sauce or base, said composition being obtainable by: i) incorporating at least one semi-refined gelling agent and/or semi-refined gelling biopolymer blend, in a mixture comprising meat and meat by-products, said mixture being used for the manufacture of the chunks; ii) mixing the manufactured chunks with a sauce or base containing no gelling agent; and iii) treating the mixture under conditions to release the pure gelling agent molecules from the chunks into the sauce or base to gelify it and to achieve chunk structure.

FIELD OF THE INVENTION

The present invention relates to pet food products containing chunks andsauce or base, and especially “chunks in jelly” products having improvedgel clearness, chunk rigidity and processability. The invention alsorelates to a process of producing such pet food products.

BACKGROUND OF THE INVENTION

Today, the petfood industry is using mainly the glucomannan orgalactomannan-kappa carrageenan mixed systems in the production ofproducts of type loaf, chunks in loaf and chunks in jelly. Typically,the jelly is made using semi refined carrageenan. The galactomannanfamily consists in guar gum, tara gum, carob gum (or locust bean gum)and cassia gum; the glucomannan consists in konjac mannan gum.

In production, the restructured meat chunks are mixed with a semirefined carrageenan liquid jelly (with other hydrocolloids and dryingredients) and go together into the can. After retorting the semirefined carrageenan makes the jelly of final product.

Because these products are using semi refined kappa carrageenan thejelly is somehow “cloudy”. This cloudiness is due to the milderextraction procedure from algae which results in a carrageenancontaining fragments of algal cell wall cellulose: of about 8-15%cellulosic material in the final composition of a typical semi refinedcarrageenan. In fact, the cellulose somehow precipitates during theretorting step and subsequently promotes the cloudiness of final gel. Inreality, the meat just released from the chunks (containing some proteinstuffs) may also complex with carrageenan cellulose precipitate,increasing even more the presence of precipitate material in the jelly.

The use of refined gelling agents, and particularly refined kappacarrageenan would improve the clearness of the final gel, but its use isquite limited in petfood industries due to high price, and semi refinedmaterial is largely used due to his low price.

Also, the chunk structure is achieved during the cooking and retortingsteps mainly through animal or vegetable protein coagulation. Thus, thequality of the obtained chunks is highly dependant on the quality of theprotein raw material. This is critical because of the variability of thesupplier sources and because of the market crisis (e.g. BSE, GMO).

Therefore, the present invention aims to improve the chunk rigidity andthe clearness, of gels and global product quality control in petfoodproducts, without using refined gelling agents and/or functionalproteins.

SUMMARY OF THE INVENTION

Accordingly, in one aspect, this invention provides a pet foodcomposition containing chunks and a clear gellified sauce or base, saidcomposition being obtainable by:

-   -   i) incorporating at least one semi-refined gelling agent and/or        semi-refined gelling biopolymer blend in a mixture comprising        meat and meat by-products, said mixture being used for the        manufacture of the chunks,    -   ii) mixing the manufactured chunks with a sauce or base        containing no gelling agent and,    -   iii) treating the mixture under conditions to release the pure        gelling agent molecules from the chunks into the sauce or base        to gellify it and to achieve the chunk structure.

In a prefered embodiment, at least one oligosaccharide oroligosaccharide blend may be further incorporated in the mixturecomprising meat and meat by-products.

Also, the sauce or base may contain a thickening and/or a stabilizingagent.

In fact, it has been surprisingly found that it was possible to preparechunks in jelly products, using semi-refined gelling agents and/orsemi-refined gelling biopolymer blend, and have in the final product avery clear gel. Indeed, during the manufacture of the composition, thecellulose material of semi refined gelling agents, especiallycarrageenan, precipitates during heat treatment (retorting) but isretained in the chunk structure which behaves like a filter and only thegelling molecules are released to the sauce or base.

Furthermore, the presence of polysaccharide in the chunk structureprovides an additional firmness due to complex formation betweensulfates groups of carrageenanes and ionic groups of proteins andpossible covalent bonds formation between residual sugar from hydrolysisof gelling agent (i.e. galactose, mannose or others oligosaccaharides)during the heat treatments and proteins. This structuration process canbe reinforced by further addition of reducing oligosaccharides (e.g.xylose, galactose, glucose, . . . ).

This petfood composition has an improved gel clearness without the needto use refined gelling agents and an improved chunk rigidity and globalproduct quality without using functional proteins.

The use of semi-refined gelling agent in the meat mix can be detected byqualitative analysis of the cellulose from gelling agent thatprecipitates in the chunk structure.

In another aspect, the invention relates to a process for preparing apet food composition containing chunks and a clear sauce or base,comprising:

-   -   i) preparing a meat mixture which comprises meat and meat        by-products and at least one semi refined gelling agent and/or        semi-refined gelling biopolymer blend    -   ii) using the meat mixture to manufacture meat chunks,    -   iii) preparing a sauce or base without adding semi refined        gelling agent    -   iv) mixing the meat chunks with the sauce or base and filling        into a container    -   v) heating the container and contents to sterilize the contents.

DETAILED DESCRIPTION OF THE INVENTION

In the present description, meat and meat by-products are understood tomean all the fleshy parts of slaughtered warm-blooded animals in thefresh state or preserved by an appropriate treatment and all theproducts and by-products arising from the processing of the bodies orbody parts of warm-blooded animals. Meat is understood to mean inparticular the meat from chickens, rabbits, bovines or ovines and offal.Offal is understood to mean lung lobes as well as livers or kidneys.Meat by-products is understood to mean the meal obtained from carcassesof the above mentioned animals. In the present description, fish andfish by-products will be regarded as coming within the definition ofmeat and meat by-products. Fish and fish by-products are understood tomean fish or fish parts in the fresh state or preserved by anappropriate treatment, as well as the by-products of their processing.Salmon or sardines can be used as fish and fish meal can be used asby-products.

Also, semi refined gelling agents are understood to mean gelling agentspartially or non refined, i.e. containing pure gelling agent moleculesthat promote a gel on the molecular basis of the transition from the“solution” to the “gel” state: it must involve some form of associationof biopolymer/polyssacharide chains (junction zones) in order to producea gel network structure (V. J. Morris, 1998, Gelation of Polysacharides,In: Functional Properties of Food Macromolecules, eds S E Hill, D ALedward & J R Mitchell, Aspen Publishers, pp. 143-226). Semi refinedgelling agents are understood to mean gelling agents partially or nonrefined such like carrageenan, alginate, agar-agar, gellan, pectin,xanthan or association of those, among others. Typically, some gums thatdo not gelify alone when in mixture with other gums, due to synergisticinteractions, present gelling properties (e.g. xanthan gun/glucomannanor galactomannan, etc) and may also be used as semi-refined gellingbiopolymer blend.

Also, oligosaccharides are understood to mean either hydrolysis productsfrom polysaccharides or added monosaccharides to react with protein.

In the present description, all the percentages are by weight unlessotherwise indicated.

According to a first aspect, the invention relates to a petfoodcomposition containing chunks and a clear gellified sauce or base, saidcomposition being obtainable by:

-   -   i) incorporating at least one semi-refined gelling agent and/or        semi-refined gelling biopolymer blend in a mixture comprising        meat and meat by-products, said mixture being used for the        manufacture of the chunks,    -   ii) mixing the manufactured chunks with a sauce or base        containing no gelling agent and,    -   iii) treating the mixture under conditions to release the pure        gelling agent molecules from the chunks into the sauce or base        to gellify it and to achieve chunk structure.

The semi refined gelling agent according to the present invention may becarrageenan (in particular kappa carrageenan), alginate, agar-agar,gellan, pectin, xanthan or association of those, among others. Thesemi-refined gelling biopolymer blend may be in the form of mixture ofgums which present gelling properties (e.g. xanthan gum/glucomannan orgalactomannan, etc).

The semi refined gelling agent or biopolymer blend may be present in anamount of up to 10% by weight, based upon the total weight.

The presence of polysaccharide in the chunk structure provides anadditional firmness due to complex formation between sulfates groups ofcarrageenanes and ionic groups of proteins and possible covalent bondsformation between residual sugar from hydrolysis of gelling agent (i.e.galactose, mannose or others oligosaccaharides) during heat treatment.

This structuration process can be reinforced by further addition ofreducing oligosaccharides. Accordingly, in a prefered embodiment, atleast one oligosaccharide or oligosaccharide blend may be furtherincorporated in the mixture comprising meat and meat by-products. Theoligosaccharide may be xylose, galactose, glucose, fructose, mannose,saccharose or other reducing pentose or hexose or association of those,for example. Preferably, the oligosaccharide may be added in an amountof 0 to 20% by weight, based upon the total weight.

Preferably, the chunks of the composition according to the inventioncontain less than 3% of particles having sizes of less than 4 mm. It isclearly understood that, depending on whether the composition isintended for cats or for dogs, the size of the chunks will be different.For dogs, 50 to 60% of the chunks will not pass through a screen with amesh opening of 16 mm. For cats, on the other hand, only 5 to 15% of thechunks will not pass through a screen with a mesh opening of 14 mm, 45to 65% of the chunks having a size of between 8 and 14 mm.

In the composition, the chunks may be present in a proportion of between20 and 70%, the remainder being the sauce or the base. In the case of acomposition with sauce, the chunks can be present in a proportion of 40to 60% whereas, with a composition with base, the chunks can be presentin a proportion of 10 to 50%.

The pet food may be produced as is conventional. Apart from the gellingagent according to the present invention, the pet food may include anyone or more of a starch source, a protein source and lipid source.

Suitable starch sources are, for example, grains and legumes such ascorn, rice, wheat, barley, oats, soy, and mixtures of these. Suitableprotein sources may be selected from any suitable animal or vegetableprotein source; for example meat and meal, poultry meal, fish meal, soyprotein concentrates, milk proteins, gluten, and the like. For elderlyanimals, it is preferred for the protein source to contain a highquality protein. Suitable lipid sources include meats, animal fats andvegetable fats.

The choice of the starch, protein and lipid sources will be largelydetermined by the nutritional needs of the animal, palatabilityconsiderations, and the type of product produced. For elderly pets, thepet food preferably contains proportionally less fat than pet foods foryounger pets. Further, the starch sources may include one or more ofrice, barley, wheat and corn.

Further, various other ingredients, for example, sugar, salt, spices,seasonings, vitamins, minerals, flavouring agents, fats and the like mayalso be incorporated into the pet food as desired.

In a preferred embodiment, the chunks are prepared from a mixturecontaining 58 to 68% of meat and meat by-products, between 16 and 25% ofcereals, between 2 and 5% of vegetable protein extracts and up to 10% ofsemi refined gelling agent, and 5 to 14% of water. The meats and meatby-products preferably comprise a minimum of 10% of pig or beef liverand from 0 to 5% of powdered pig or beef plasma and the cereals arepresent in a proportion of at least 10%, the said cereals being wheat,maize or rice flours, which makes it possible to ensure that the chunkat the cutting off has a sufficient texture and to avoid the productionof fines and of tears. The chunks can additionally contain up to 3% ofdyes, vitamins and inorganic salts.

The powdered plasma can advantageously be substituted by at least 2% ofvegetable protein extracts which play the same role as the plasma.Furthermore, the present invention provides the possibility to replacetotally the animal or vegetal functional proteins (i.e. plasma, soya, .. . )

The chunks present in the composition can also be prepared from amixture additionally containing between 0 and 5% of vegetable proteinextract. Vegetable protein extract may be any product, of plant origin,the proteins of which have been concentrated by an appropriatetreatment, which contain at least 50% of crude proteins with respect tothe dry matter and which may have been restructured. The proteins usedare, for example, wheat or maize gluten or soya isolate.

In the mixture for preparing the chunks, the water content can beadjusted to between 0 and 15% according to the meat and cereal contents,in order to obtain a final moisture level of the chunks of preferablybetween 50 and 60% and more preferably between 52 and 58%, in order toensure a correct content of the emulsion in the manufacturing process.

Before mixing the meat and meat by-products, a size reduction of thesaid meats may be carried out in order to arrive at sizes of the orderof 12 mm. The meats (and optionally also the fish) are then mixed withthe other ingredients (optionally also the vegetable protein extracts)of the chunk composition until homogenized, in order to obtain anelastic paste. Emulsification may then be carried out and the emulsifiedpaste may then be pumped, with or without deaeration, to a continuousshaping system which makes it possible to extrude puddings. The puddingpaste thus obtained may be cooked by any continuous cooking system (forexample, hot air, steam, hot air and steam or microwave system) in orderto obtain a core temperature of between 80 and 95° C. The puddings arethus congealed by coagulation and can be sliced at the outlet of thecooking device. The cooked coagulated paste is then continuously cut atthe outlet of the cooking system into congulated pieces with a length of40 to 400 mm. The elongated pieces are then hardened by cooling to atemperature of between 10 and 40° C.: the cooling is preferably carriedout with water by spraying or immersion in order to prevent the chunksfrom sticking to one another. It finally remains to cube the cooledpieces. In order to do this, use is made of a cuber known in the stateof the art, such as the Urschel cuber.

According to the present invention, the viscosity of the meat mixtureand the quality of the chunk cutting (i.e. less fines formation, bettershape finition) are improved by the presence of the semi-refined gellingagent and/or added oligosaccharides, even in the absence of vegetable oranimal functional protein.

The chunks thus obtained are mixed in a way known per se with the sauceor the base. Sauce is understood to mean a mixture containing up to 98%of water, the remainder being one or more thickeners, such as gums, dyesand flavouring agents. Base is understood to mean a mixture based on 60to 80% of water and 20 to 40% of finely ground meats, the remainderbeing thickeners, dyes and aromas.

The sauce or base according to the present invention does not containany gelling agent that promote a gel network as previously defined.Preferably, it contains a thickening and/or a stabilizing agent,suitable gums are locust bean gum, guar gum, cassia gum, carob gum andKonjac gum for example.

The pet foods are then filled into cans or other containers, thecontainers sealed, and the mixture is heat treated under conditions torelease the pure gelling agent molecules from the chunks into the sauceor base to gellify it. Preferably, the product is retorted in the normalmanner, e.g. the composition is finally sterilized conventionally at atemperature of between 120 and 135° C. for 20 to 100 min. Suitableequipment is commercially available.

The following examples are given by way of illustration only and in noway should be construed as limiting the subject matter of the presentapplication. All percentages are given by weight unless otherwiseindicated.

EXAMPLES Examples 1 to 5

The gelling system used is composed of semi refined kappacarrageenan/semi refined carob gum/potassium chloride. The carob gum canbe replaced by other galactomannans like tara gum or cassia gum andglucomannans like konjac gum.

The viscosity of the jelly can be adjusted using guar gum in order toproceed to filling cans either one step or two step filling.

Example 1

Jelly Semi refined carob gum   0.5% Potassium chloride   0.15% Liquidcaramel   0.3% Flavor system   0.5% Water  97.35% Chunk Semi refinedkappa carrageenan  1-1.5% Animal meats 78.5-79% Meat meals    10% Plasmapowder   1.5% Flavor system     3% Salt   1.5% Colorant     1% Water    3%

Example 2

Jelly Cassia gum  0.5% Guar gum 0.25% Potassium chloride 0.15% Liquidcaramel  0.3% Flavor system  0.5% Water 97.1% Chunk Recipe as in example1

Example 3

Jelly Konjac gum  0.5% Potassium chloride  0.15% Liquid caramel  0.3%Flavor system  0.5% Water 97.35% Chunk Recipe as in example 1

Example 4 Cat Composition “Chunks in a Jelly”

Jelly Semi refined carob gum   0.5% Potassium chloride   0.15% Liquidcaramel   0.3% Flavor system   0.5% Water  97.35% Chunk Semi refinedkappa carrageenan  1-1.5% Animal meats 78.5-79% Meat meals    10% Xylose  1.5% Flavor system     3% Salt   1.5% Colorant     1% Water     3%

Example 5 Cat Composition “Chunks in a Jelly”

Jelly Semi refined carob gum   0.5% Potassium chloride   0.15% Liquidcaramel   0.3% Flavor system   0.5% Water  97.35% Chunk Semi refinedkappa carrageenan  1-1.5% Animal meats 78.5-79% Meat meals     9%Galactose   2.0% Plasma powder   0.5% Flavor system     3% Salt   1.5%Colorant     1% Water     3%

Example 6 Cat Composition “Chunks in a Sauce”

A mixture is prepared from 73% of animal meats, 16% of wheat flour, 2%of powdered beef plasma, 6.8% of water, 2.2% of dyes and 1% of semirefined iota/kappa carrageenan, 1% xylose, vitamins and inorganic salts.This mixture is emulsified at 12° C. and extruded in the form of apudding paste. This pudding paste is cooked at a temperature of 90° C.,and pieces with a length of 80 mm are cut. They are cooled to 30° C. andcut in order to obtain chunks. 45% of these chunks are mixed with 55% ofsauce prepared from 98% of water, 1% of dye and 1% of guar gum. Tinplatecans are filled and sterilized.

Example 7 Cat Composition “Chunks in a Sauce”

A mixture is prepared from 73% of animal meats, 16% of wheat flour, 2%of powdered beef plasma, 6.8% of water, 2.2% of dyes and 1% of semirefined iota/kappa carrageenan, vitamins and inorganic salts. Thismixture is emulsified at 12° C. and extruded in the form of a puddingpaste. This pudding paste is cooked at a temperature of 90° C., andpieces with a length of 80 mm are cut. They are cooled to 30° C. and cutin the cuber in order to obtain chunks. 45% of these chunks are mixedwith 55% of sauce prepared from 98% of water, 1% of dye and 1% of guargum. Tinplate cans are filled and sterilized.

Example 8 Cat Composition “Chunks in a Base”

A mixture is prepared from 56% of animal meats, 16% of wheat flour, 2%of plasma, 10.8% of water and 2.2% of dyes, 1% of semi refined kappacarrageenan, 3% glucose and vitamins and inorganic salts. Thepreparation is then carried out as in Example 6, in order to obtainchunks. 30% of these chunks (having a water content of 58%) isincorporated in a base prepared from 23% of poultry carcass, 1% of guargum, 1% of dye and aroma and 75% of water. Tinplate cans are then filledand sterilized.

Example 9 Cat Composition “Chunks in a Base”

A mixture is prepared from 56% of animal meats, 13% of fish, 16% ofwheat flour, 2% of plasma, 10.8% of water and 2.2% of dyes, 1% of semirefined kappa carrageenan and vitamins and inorganic salts. Thepreparation is then carried out as in Example 6, in order to obtainchunks. 30% of these chunks (having a water content of 58%) isincorporated in a base prepared from 23% of poultry carcass, 1% of guargum, 1% of dye and aroma and 75% of water. Tinplate cans are then filledand sterilized.

Example 10 Dog Food Composition

69% of animal meats is mixed with 20% of wheat flour, 1% of powderedbeef plasma, 7.8% of water and 2.2% of dyes, 1% semi refined kappacarrageenan, and vitamins and inorganic salts. This mixture isemulsified at 12° C. and extruded in the form of a pudding paste. Thispudding paste is cooked at a temperature of 90°, and pieces with alength of 80 mm are cut. They are cooled and cut in order to obtainchunks. 50% of these chunks are mixed with 50% of sauce prepared from98% of water, 1% of dye and 1% of guar gum. Tinplate cans are filled andsterilized.

Example 11 Qualitative Analysis of the Cellulose from Kappa Carrageenanin the Chunks

The use of semi refined kappa carrageenan in the meat mix can be checkedby qualitative analysis of the cellulose from kappa-carrageenan thatprecipitates in the chunk structure. The methodology used is thefollowing:

-   -   separation by sieving of chunks from hot liquid jelly    -   extraction from the chunks the acid insoluble matter (cellulose        fibers):        -   200 g of product+200 ml concentrated sulfuric acid+600 ml            desionized water,        -   stirring and heating 100° C. during 6 hours        -   stirring during one night        -   strirring and heating 100° C. during 1 hour        -   flitration        -   rinsing with 2 liters of desionized water        -   drying 2 hours 102° C.        -   removing of fat in Buchi extraction station with petroleum            benzine 2 hours        -   drying 2 hours 102° C.        -   powder    -   qualitative analysis by RMN of the presence or not of cellulose        from semi refined kappa carrageenan. (Glyn O. Phillips, 1996,        Gums and Stabilisers for the Food Industry, 8, pp 403).

1. A pet food composition comprising meat chunks and a clear gellifiedportion free of cellulose, said composition being prepared by a methodcomprising the steps of: incorporating at least one semi-refined gellingagent in a mixture comprising meat and meat by-products, and using saidmixture for manufacture of meat chunks, mixing the manufactured chunkswith a component containing no gelling agent and being selected from thegroup consisting of a thickening agent, a stabilizing agent, a sauce anda base and, heat treating the mixture under conditions to release puregelling agent molecules from the chunks into the component to gellifythe component achieve a chunk structure and cause cellulose present inthe gelling agent to precipitate during treatment, the chunk structurepreventing the cellulose present in the gelling agent from beingreleased into the component while allowing the pure gelling agentmolecules to be released into the component.
 2. A pet food compositionaccording to claim 1 wherein the semi-refined gelling agent is selectedfrom the group consisting of, alginate, agar-agar, gellan, pectin, andxanthan.
 3. A pet food composition according to claim 1, wherein thesemi-refined gelling agent is a biopolymer blend in the form of amixture of gums which have gelling properties.
 4. A pet food compositionof claim 3 wherein the mixture of gums is selected from the groupconsisting of xanthan gum, glucomannan, and galactomannan.
 5. A pet foodcomposition according to claim 1, wherein the semi-refined gelling agentis incorporated in an amount up to 10% by weight, based upon the totalweight of the mixture.
 6. A pet food composition according to claim 1,wherein at least one oligosaccharide is further incorporated in themixture comprising meat and meat by-products.
 7. A pet food compositionaccording to claim 6, wherein the oligosaccharide is selected from thegroup consisting of xylose, galactose, glucose, fructose, mannose,saccharose, reducing pentose and hexose.
 8. A pet food compositionaccording claim 1, wherein the component comprises at least one agentselected from the group consisting of a thickening agent and astabilizing agent.
 9. A pet food composition according to claim 1,wherein the component is a sauce and the chunks are combined with thecomponent in an amount of from 40% to 60%, by weight.
 10. A pet foodcomposition according to claim 1 wherein the semi-refined gelling agentis a semi-refined gelling biopolymer blend.
 11. A pet food compositionaccording to claim 1 wherein the component is a sauce.
 12. A pet foodcomposition according to claim 1 wherein the component is a base.
 13. Apet food composition according to claim 1 wherein the component is abase and the chunks are combined with the base in an amount of 10% to50% by weight, based upon the total weight.
 14. A pet food productcomprising solid meat-like chunks having chunk structures in a cleargel, free of cellulose, and including selected from the group consistingof a thickening agent, a stabilizing agent, a sauce and a base, whereinthe chunks contain cellulose precipitated from a source comprising asemi-refined gelling agent, the chunk structures preventing thecellulose from being released from the chunks while allowing puregelling agent molecules of the semi-refined gelling agent to be releasedinto the component.
 15. A product according to claim 14 wherein the gelcomprises gelling molecules released from the chunk structure when thecellulose is precipitated.
 16. A product according to claim 14, whereinthe cellulose and gelling molecules are derived from a common sourcecomprising the semi-refined gelling agent.
 17. A pet food compositionaccording to claim 16 wherein the semi-refined gelling agent is asemi-refined gelling biopolymer blend.
 18. A product according to claim14 comprising the semi-refined gelling agent in an amount up to 10% byweight, based upon total weight of the product.